Apparatus for treating gas



June 2, 1931. URQUHART 1,808,087

' APPARATUS FOR TREATING GAS Filed Jan. 29, 1929 4 Sheets-Sheet l dbtomJune 2, 1931. K. M. URQUHART APPARATUS FOR TREATING GAS 4 Sheets-Sheet 2Filed Jan. 29, 1929 gwvwntoz- En/ref? dyad? June 2, 1931. K, URQUHART1,808,087

APPARATUS FOR TREATING GAS Filed Jan. 29. 1929 4 Sheets-Sheet 3 June 2,1931. K. M. URQUHART 1,808,087

APPARATUS FOR TREATING GAS Filed Jan. 29, 1929 4 Sheets-Sheet 4 i bedesired.

Patented June 2, 1931f PATENT mm:

\ I. UBRUELB'I, OI MARSHALL, OnAHOIA nrrnm'rus iron rnna'rme ensApplication 1m; January 29, 1929. Serial No. 835,801.

This invention relates to a method of removing condensable hydrocarbonsfrom gas such as natural gas and more particularly to the removal ofhydrocarbons heavier than ethane. Coincidentally the invention embracesa method of removing other condensable substance from such gases, suchas water vapor. In the conception of this method certain forms ofappar'atushave been developed peculiarly adapted to the special problemsencountered therein, and this apparatus is included in this disclosureas being preferable in the practice of this method.

One object of this invention is to make it economically profitable tostrip gas of the gasoline content to the benefit of the gas remaining inmany cases and to the profit of the gas campanies, thus enabled toproduce a high grade of gasoline.

A further object of the invention is to remove moisture content fromnatural gases so as to leave a very low percentage of moisture in thetreated gas. A further object of this invention is to remove such othersolidifiable or condensable substances asmay Another object of theinvention is to accomplish the foregoing objects with little expenditureof capital in plant fixtures and with a low cost of operation. Furtherobjects of the invention will be obvious from the following detailedspecification and claims.

I In order to enable others to understand and practice the invention Ihave constructed certainfigures as follow.

ly the plant in itsentirety with certain parts e ls'hows somewhatdiagrammaticaltion of the heat exchanger device with units in place.Figures 8 and 9 are respectively isometric views and sectional views ofa por tion of a cooling system for the raw gas.

In Fi re 1, 10 designates the pipe through which t e raw gas enters thedevice.) 11 is a tower for the stripping of the gas wherein 12 arebubble plates of'known design through which the gas (passes upwardlypast a. plate 18 is a base outlet which may be float controlled toremove water. from the lower end of the tower 11.

19 are outlets for the removal of gasoline from various levels which maybe controlled by float controlled device 20.

21 'is. another outlet where Water may be removed. 22 is a liquid levelcontrolled outlet for the removal of a higher boiling fraction which iscondensed in the reflux condenser or upon the plates 16.

23 is a like device'for the removal of lower boiling fractions.

24 is a gas outlet pipe leading from the top of column 11 to lowtemperature heat exchanger 25, through this, through connection 26 intohifgh temperature heat exchanger 27 and out o the same to the point ofconsumption through pipe 28.

For the rst cooling of the gas there is provided a cycle of gasolinewhich leaves the lower end of the column 11 at 3O, is impelled by pump31 and passes through high tern-- perature heat exchanger 27 to becooled by the out flowing lean' gas, from there it-passes through hightemperature cooler 32 where it is further chilled by a refrigerationsystem to be described later. It then passes into and through and mmthere through low temperature cooler 33. As will be obvious to oneskilled in the art these four devices, 27, 32, 25 and 33,

may be enclosed in one case with suitable connections to eachportion, asshown in Figure The chilled gasoline then passes up through pipe 34 andis released on the top of the highest inverted cone 14. From there itflows down over the cones and chills the upwardly flowing gases so thatthe major portion of the moisture content therein is frozen or depositedas slush upon the cones 14, from which they are readily Washed down bythe down flowing gasoline. The higher boiling portions of gasoline inthe upwardly flowing raw gas Will be condensed while the lower boilingportions of gasoline in the liquid will be vaporized.

As was indicated previously, the excess gasoline or make is removedthrough pipes 19.

The cooling of the system is by a closed cycle refrigeration systemwherein compressed and preferably liquefied refrigerant flows out ofrefrigerant condenser 40 through pipe 41 into the reflux condenser 17where it chills the gas to remove the last low boiling fractions ofgasoline. Another branch of pipe 42 carries liquid refrigerant tocoolers 32 and 33 to chill the cyclic flowing gasoline as beforedescribed.

From 32 and 33 the gaseous refrigerant flows back to the compressionsystem 43 having a first and second low pressure means and a highpressure cylinder or the like. The refrigerant from the reflux condenser17 likewise flows back through 44 to the compressor. The compressorobviously may be constructed in known manner to obtain'the desiredeffect of compressing the warmed refrigerant gas adequately so that thesame will be condensed when cooled in condenser 40.

In order to make this system operate automatically with very littlemanual control an automatic system of valves may be installed to operatesomewhat as follows.

. valve 60 may be inserted in Thermostat 50 may operate expansion valve51, thus controlling. the temperature.

maintained in the high temperature cooler 32.

Thermostat 52 will likewise control ex.

pansion valve 53 by the temperature within the low temperature cooler33. Thermostat 54 may be made to control the cyclic outlet valve 55 orthe pump 31 or both, in order that the temperature of the gas'flowingupwardly through base plate 15 may be that desired.

Thermostat 56 may control the expansion valve 57 so that refluxcondenser 17 is kept at the desired temperature. Back pressure therefrigerant line from 32 to 43 to control the pressure of theevaporating refrigerant in the high temperature cooler 32. Analogouslyback pres sure valve 61 may be inserted between 33 and low temperatureheat exchanger 25 f 43 and back pressure valve 62 functions the same forthe refrigerant passing from 17 to 43.

Obviously there may be made many changes in all of the parts shown butpreferably they are essentially as shown and described. In theconstruction of the coolers and heat exchangers it is preferable to havethe separators or tubes of such a nature that they can be removedseparately for repairs or for replacement. In order to do so I hageconstructed them as shown imFigures 2 to The tube sheet is composed oftwo main parts. is the tube sheet having separate ribs 71, and 73 is atube sheet cap which is secured to the tube sheet by bolts which may beinserted through holes 74 and into holes 75 as is obvious in Figure 7.

The extremely long tube made long because corrugations maintainturbulence is corrugated and the last' corrugation, or if desired all ofthe corrugations, are at a slight'angle and are so fashioned that theside of them crimped to the tube contacts to fit flush with the wedge 71when the same is forced into position. Gaskets notshown are fitted overthe ends ,77 so that when the tubes 76 are inserted and wedges forced inthere will be afirm, gas tight connection between the tube ends 77 andtube sheet 70. This connection may be assisted by having the ends 77 ofthe tube 76 fashioned to have turned in lips 78 to fit into grooves 79in the tube sheet 70. These will assist in making a tight connection andprevent collagse of tube ends 77 under wedging action of f thetemperature within the chamber 11 around the bafiies 14 is below thefreezing point of water there will be a formation of ice therein if theraw gas contains any considerable quantities of water. vapor. In theusual device of this type the formin g ice would eventually clog thepassageway and stop the flow of gas, For this reason I have invented anew and improved form of .ap'paratusto be used in the practice of thisinvention and in other conditions where similar efiects obtain.

13 will be drained out through the base of the column 11 at point 18.

It is to be understood that I do not wish to be limited in the practiceof'my invention Inverted cones 14 are supported preferably 1 to thespecific procedure describedorto the specific apparatus shown,' though Ihave v f found the apparatus as shown to be preferable in the practiceof this invention. I What I have invented and desire to protect byLetters Patent'is: j 1. An ap aratus for the removal of condensable sustance from a gas which comprises a tower having a gasinlet near the asethereof, (quid outlets below said gas inlet, one of sai liquid outletsleading to an impeller which drlves the liquid removed through chillingdevices, a liquid inlet at a point above the gaseous inlet where thechilled liguid is allowed to flow counter to the upward owing gas withinthe tower, baflles between the gas inlet and the liquid inlet, a: plateabove said liquid inlet preventing sub stantial down flow of liquid butpermitting 0 up flow of gas, bubble plates above said plate,

- a reflux condenser above said bubble plates and a gaseous outlet inthe upper ortlon of said tower from which a pipe lea s the gas throughtwo heat exchangers in series, where the liquid before mentioned isconsequently chilled by the out flowin gas, and a cooler operated by arefrigerant interposed between said two heat exchangers.

2. An apparatus as in claim 1 wherein a second cooler is inter os'edbetween the lower temperature heat exc anger and the tower to cool thesaid liquid still further before it enters the tower.

3. An apparatus as in claim 1 wherein automatic valve means control theflow of liquid through said im eller and the temperature maintained by te refrigerant within the specified devices which are cooled by saidrefrigerant. 40 In testimony whereof I aifix my signature.

KENNETH M. URQUHART.

